Journal articles: 'Crystal development'

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Brubaker, Curt L., and Harry T. Horner. "Development of epidermal crystals in leaflets of Stylosanthes guianensis (Leguminosae; Papilionoideae)." Canadian Journal of Botany 67, no. 6 (June 1, 1989): 1664–70. http://dx.doi.org/10.1139/b89-210.

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In developing leaflets of Stylosanthes guianensis (Aubl.) Sw., twin prismatic calcium oxalate crystals form in adaxial and abaxial epidermal crystal idioblasts. These cells eventually die and collapse, leaving the crystals embedded in a matrix of cutin and cell-wall materials. Adaxial crystal idioblasts develop above large conical cells that, in turn, are interspersed among smaller, multiple-layered palisade parenchyma. Abaxial crystal idioblasts develop beneath a uniseriate layer of large horizontally branched cells abutting the abaxial epidermis. Spongy parenchyma occupies the middle mesophyll above the layer of branched cells. The abaxial crystals and the branched cells of the lowermost mesophyll develop simultaneously. Adaxial crystals and the conical cells develop later and in conjunction with each other. In mature leaflets, the adaxial and abaxial crystals and their associated collapsed crystal idioblasts form networks, the interstices of which are occupied by either single stomates and accompanying epidermal cells (adaxial) or clusters of stomates and accompanying epidermal cells (abaxial). Epidermal crystals are known from other Leguminosae; however, to our knowledge this is the first report where epidermal crystal development involving cell death and collapse is correlated with two types of specialized mesophyll cells.

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Rodriguez-Navarro, Alejandro. "Model of textural development of layered crystal aggregates." European Journal of Mineralogy 12, no. 3 (May 31, 2000): 609–14. http://dx.doi.org/10.1127/ejm/12/3/0609.

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Skomorovsky, Valery, Galina Kushtal, and Lyubov Tokareva (Lopteva). "Iceland spar and birefringent filter (BF) development." Solar-Terrestrial Physics 8, no. 1 (March 25, 2022): 69–84. http://dx.doi.org/10.12737/stp-81202209.

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Birefringent crystals for BF are required to provide the necessary linear aperture, wavefront quality, and filter transmission in a given spectral region. Based on the review of foreign and domestic BF developments, the difficulties in using crystals from known deposits are examined. The Institute of Solar-Terrestrial Physics has developed BFs with extreme characteristics, using an innovative method for enriching crystals from East Siberian deposits and new methods for optical treatment and control of BF elements. We present the characteristics of the filters. Further progress in the creation of BFs in our country depends on the availability of necessary synthetic crystals and natural crystal of Iceland spar, which turned out to be a difficult fate in Russia.

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Anand, Rachna, Arun Kumar, and Arun Nanda. "Pharmaceutical Co-Crystals - Design, Development and Applications." Drug Delivery Letters 10, no. 3 (September 10, 2020): 169–84. http://dx.doi.org/10.2174/2210303109666191211145144.

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Background: Solubility and dissolution profile are the major factors which directly affect the biological activity of a drug and these factors are governed by the physicochemical properties of the drug. Crystal engineering is a newer and promising approach to improve physicochemical characteristics of a drug without any change in its pharmacological action through a selection of a wide range of easily available crystal formers. Objective: The goal of this review is to summarize the importance of crystal engineering in improving the physicochemical properties of a drug, methods of design, development, and applications of cocrystals along with future trends in research of pharmaceutical co-crystals. Co-crystallization can also be carried out for the molecules which lack ionizable functional groups, unlike salts which require ionizable groups. Conclusion: Co-crystals is an interesting and promising research area amongst pharmaceutical scientists to fine-tune the physicochemical properties of drug materials. Co-crystallization can be a tool to increase the lifecycle of an older drug molecule. Crystal engineering carries the potential of being an advantageous technique than any other approach used in the pharmaceutical industry. Crystal engineering offers a plethora of biopharmaceutical and physicochemical enhancements to a drug molecule without the need of any pharmacological change in the drug.

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Patel, Ekta C., Hemangi S. Patel, Mehul N. Patel, Jenee R. Christian, and B. N. Suhagia. "Development, Characterization and Analysis of Azelnidipine Co-Crystals." Research Journal of Chemistry and Environment 26, no. 6 (May 25, 2022): 15–23. http://dx.doi.org/10.25303/2606rjce15023.

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Azelnidipine, an anti-hypertensive drug of dihydropyridine class, has low solubility and high permeability drug (class-2) and thus often shows dissolution rate-limited oral absorption and high variability in pharmacological effects. The purpose of study was to prepare co-crystals of AZL to enhance its solubility. Co-crystals were prepared by solvent evaporation method using different co-crystal formers. The prepared co-crystals were evaluated for solubility. The solid state property was characterized by microscopy, differential scanning calorimetry (DSC) and Fourier transfer infrared spectroscopy (FTIR). It was observed that the solubility of AZL co-crystals was significantly more than AZL. Co-crystal using succinic acid and saccharine gave maximum solubility. The microscopy, FTIR and DSC and studies of cocrystal confirmed the formation of co-crystals and indicated that new interactions were formed. In conclusion, co-crystals of AZL lead to the solubility enhancement and this can be further explored to study the impact of increased solubility on the bioavailability of AZL.

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Punitha, P., and S. Senthilkumar. "CRYSTAL DEVELOPMENT, THERMAL AND CRYSTALLINE PERFECTION OF POTASSIUM MAGNESIUM COBALT SULFATE HEXAHYDRATE MIXED CRYSTALS." Rasayan Journal of Chemistry 14, no. 04 (2021): 2810–19. http://dx.doi.org/10.31788/rjc.2021.1446571.

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Potassium magnesium cobalt sulfate hexahydrate (KMCS) was synthesized and single crystals were obtained with a slow evaporation solution growth technique (SESGT). KMCS empirical formula is K2Mg0.26Co0.74(SO4)26H2O with the weight of equation 428.34. KMCS crystal exposed monoclinic space groupP21/c, a = 6.1457, b = 12.2208, c = 9.0677, a = g = 90 °, b = 105 °, V = 657.87, Z = 2, 2.162 Mg m-3, in pink colour.The rate of frequency reduction found in powder indicates the crystal stress resulting from the processing of grown crystals. Single crystals are performed with FT-IR and UV-vis spectral studies. High-resolution X-ray diffraction (HRXRD) indicates prevalent site occupation substitution Co (II). For powder X-ray diffraction (XRD) results in the development of crystal stress due to the formation of single crystals. Electron microscopy scanning (SEM) tests the morphological changes in the exterior. The introduction of dopant into the crystalline medium has been verified by energy-dispersive X-ray spectroscopy (EDS). TG-DTA research has been conducted for single crystal thermal studies.

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Lim, L. C., S. Zhang, Y. X. Xia, D. H. Lin, and N. H. L. Goh. "Pb(Zn1/3Nb2/3)O3–PbTiO3single crystal and device development." Journal of Advanced Dielectrics 04, no. 01 (January 2014): 1350026. http://dx.doi.org/10.1142/s2010135x13500264.

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This paper describes recent device developments with relaxor ferroelectric Pb ( Zn1/3Nb2/3) O3– PbTiO3(PZN–PT) single crystals carried out at Microfine Materials Technologies Pte. Ltd, Singapore. Promising [011]-poled transverse cuts of PZN–PT single crystals and the results on the effect of electric field and axial compressive stress on the rhombohedral-to-orthorhombic ( R – O ) phase transformation behavior of such cuts are presented and discussed. The single crystal devices described include a compact low-frequency broadband power-efficient underwater tonpilz projector, high sensitivity shear accelerometers and acoustic vector sensors (AVS). The unique characteristics offered by these PZN–PT single crystal devices are highlighted, which serve as examples of new-generation piezoelectric devices and systems for a wide range of demanding applications.

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DYBING, STEPHEN T., STEVEN A. BRUDVIG, JAMES A. WIEGAND, and EMIL A. HUANG. "A Simple Method for Estimating the Extent of Surface Crystal Development on Colored Cheddar Cheese." Journal of Food Protection 49, no. 6 (June 1, 1986): 421–22. http://dx.doi.org/10.4315/0362-028x-49.6.421.

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A simple, non-destructive method for estimating the extent of crystal development as white specks on the surface of colored Cheddar cheese is described. This method involves photocopying the surface of the cheese with a photocopier set at an exposure calibrated to clearly show the crystals. The photocopies of the cheese surface are then compared to a series of photocopies showing designated increases in crystal growth. Crystal development was rated as follows: 0 = no crystals, 1= light, 2 = medium, 3 = heavy, and 4 = very heavy to encrusted crystal development. The method does not disrupt or destroy the environmental conditions existing in the cheese package, allowing extended shelf life studies to be done on the same piece of cheese. However, the photocopy technique may not work as well with white cheese or cheeses without flat surfaces.

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Bondokov, Robert T., Kasey Hogan, Griffin Q. Norbury, Justin Mark, Sean P. Branagan, Naoki Ishigami, James Grandusky, and Jianfeng (Jeff) Chen. "(Invited) Development of 3-inch AlN Single Crystal Substrates." ECS Meeting Abstracts MA2022-02, no. 37 (October 9, 2022): 1346. http://dx.doi.org/10.1149/ma2022-02371346mtgabs.

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Aluminum nitride (AlN) holds great promise as a substrate for electronic devices such as high-power switches, high power density, high frequency and high operating temperature devices for RF. This promise is largely due to its superior properties, for instance its ultra-wide bandgap (UWBG) of 6.2 eV, high thermal conductivity (> 290 W/m*K), high melting point (> 2800°C), relatively good chemical resistance, similarity of its lattice structure and parameters to that of Gallium nitride (GaN), high hardness value of about 12 GPa (at 1 N using Vickers indenter), etc. Presently AlN substrates are successfully used for fabrication of ultraviolet (UV) light emitting diodes (LEDs) operating at wavelengths shorter than 280 nm, i.e., in the UVC region of the spectrum. The AlN-based UVC LEDs are employed in water disinfection, surface cleaning, air purification, and environmental sensing. Several factors including substrate availability, size, production capacity, quality, and cost influence the commercialization of the aluminum nitride both as an UWBG and as an opto-electronic substrate. In this work we present the present and future outlook for the AlN substrates made using Physical Vapor Transport (PVT) growth technique. The PVT crystal growth method of aluminum nitride is carried out in a Tungsten crucible that accommodate the AlN source material as well as the (0001) oriented AlN seed. The thermal gradient is provided by an rf-heating plus appropriate shielding and insulation. In this setup, the sublimed source material is transported to the Al-polar face of the seed where it incorporates into a single crystal. The AlN crystals are then oriented, sliced, and polished. The resulting 2-inch substrates are tested to meet certain specification needed for further epitaxial growth and LED processing. The two-inch AlN wafer specification as well as number of physical properties and purity were previously reported [1]. In addition to the 2-inch AlN crystal growth there is an ongoing effort to increase the substrate diameter. Large-diameter (e.g. 100 mm) AlN substrates are a practical requirement benefiting high power electronic devices. Again, PVT growth method is used to expand the crystal size and diameter. However, several challenges have yet to be resolved en route to 100 mm diameter crystals. These challenges are associated with increased thermally induced stress, the need for better control of the axial/radial thermal gradients, vendor ability to provide materials, maintaining crystal quality during expansion, etc. Our PVT growth technique demonstrates high crystal growth yield which allows to contain relatively low production cost. Furthermore, we have established a high-capacity process capable to produce many thousands of 2-inch AlN substrates per year. Our current crystal growth process also demonstrated greater than 3-inch diameter single-crystal AlN substrates; properties of such wafers will be reported. Robert T Bondokov et al 2021 ECS Trans. 104 37

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T, Mamatha, Sama M, and Husna K. Qureshi. "Development and Evaluation of Mesalamine—Glutamine Cocrystal Tablets for Colon Specific Delivery." International Journal of Pharmaceutical Sciences and Nanotechnology 10, no. 5 (September 30, 2017): 3866–74. http://dx.doi.org/10.37285/ijpsn.2017.10.5.8.

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The objective of the work was to develop the co-crystal formulation of mesalamine with glutamine. It was done to enhance dissolution rate, solubility and physicochemical properties to be used in pharmaceutical composition (tablet) for colon targeting. Co-crystal preparation was carried out by liquid assisted grinding method using glutamine as a co-crystal former (1:1 stoichiometric ratio) and acetonitrile as a solvent giving maximum solubility and dissolution rate. The formation of the co-crystals was confirmed by Fourier Transform – Infra Red spectrometry, Differential Scanning Calorimetry and Powder X-Ray Diffraction. Pre-compression studies included measure-ment of bulk density, tapped density, angle of repose, Hausner’s ratio and compressibility index. The tablets were prepared by direct compression. Post compression parameters for uncoated tablets included hardness, size and thickness, friability and weight variation. Enteric-coated tablets were prepared by dip-coating process using Eudragit RSPO, Triethyl citrate and isopropyl alcohol mixture as coating solution. The coated tablets were further evaluated for disintegration and dissolution testing. All the results were found to be under specified limits. Finally, co-crystal tablets were compared with marketed formulation. In vitro dissolution rate of optimized mesalamine co-crystal tablet was comparatively higher than marketed formulation, which reflects improvement in solubility. Glutamine has good anti-inflammatory property. Formulation with glutamine as co-crystal added more efficacies to mesalamine for treatment in colon related inflammatory diseases. It was concluded that stable co-crystals of mesalamine -glutamine having better anti-inflammatory property, increased solubility and improved in vitro dissolution of mesalamine can be successfully prepared.

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Alcorn, Thomas, and Douglas H. Juers. "Progress in rational methods of cryoprotection in macromolecular crystallography." Acta Crystallographica Section D Biological Crystallography 66, no. 4 (March 24, 2010): 366–73. http://dx.doi.org/10.1107/s090744490903995x.

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Cryogenic cooling of macromolecular crystals is commonly used for X-ray data collection both to reduce crystal damage from radiation and to gather functional information by cryogenically trapping intermediates. However, the cooling process can damage the crystals. Limiting cooling-induced crystal damage often requires cryoprotection strategies, which can involve substantial screening of solution conditions and cooling protocols. Here, recent developments directed towards rational methods for cryoprotection are described. Crystal damage is described in the context of the temperature response of the crystal as a thermodynamic system. As such, the internal and external parts of the crystal typically have different cryoprotection requirements. A key physical parameter, the thermal contraction, of 26 different cryoprotective solutions was measured between 294 and 72 K. The range of contractions was 2–13%, with the more polar cryosolutions contracting less. The potential uses of these results in the development of cryocooling conditions, as well as recent developments in determining minimum cryosolution soaking times, are discussed.

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BAERT, KASPER, WIM LIBAERS, BRANKO KOLARIC, RENAUD A. L. VALLÉE, MARK VAN DER AUWERAER, KOEN CLAYS, DIDIER GRANDJEAN, MARCEL DI VECE, and PETER LIEVENS. "DEVELOPMENT OF MAGNETIC MATERIALS FOR PHOTONIC APPLICATIONS." Journal of Nonlinear Optical Physics & Materials 16, no. 03 (September 2007): 281–94. http://dx.doi.org/10.1142/s0218863507003779.

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In this manuscript, the synthesis and characterization of superparamagnetic particles and their silica-coated counterparts as building blocks for magnetic photonic crystals is fully described. The advantages and disadvantages of the presented synthetic method are discussed. Preliminary results considering the presence of magnetic species within a photonic crystal are also presented. Suppression of emission of the quantum dots within photonic crystals is attributed to a decrease of the number of available photonic modes for radiative decay. The presence of materials with permanent magnetic moments within photonic crystals shows that suppression of their emission is scaled with the strength of the magnetic field.

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Skomorovsky, Valery, Galina Kushtal, and Lyubov Tokareva (Lopteva). "Iceland spar and birefringent filter (BF) development." Solnechno-Zemnaya Fizika 8, no. 1 (March 25, 2022): 70–86. http://dx.doi.org/10.12737/szf-81202209.

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Birefringent crystals for BF are required to provide the necessary linear aperture, wavefront quality, and filter transmission in a given spectral region. Based on the review of foreign and domestic BF developments, the difficulties in using crystals from known deposits are examined. The Institute of Solar-Terrestrial Physics has developed BFs with extreme characteristics, using an innovative method for enriching crystals from East Siberian deposits and new methods for optical treatment and control of BF elements. We present the characteristics of the filters. Further progress in the creation of BFs in our country depends on the availability of necessary synthetic crystals and natural crystal of Iceland spar, which turned out to be a difficult fate in Russia.

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Al-Dulaimi, Amal Fakhrulddin, Myasar Mohammed Al-Kotaji, and Faris Thanoon Abachi. "Development of novel paracetamol/naproxen co-crystals with an improvement in naproxen solubility." Iraqi Journal of Pharmaceutical Sciences ( P-ISSN 1683 - 3597 E-ISSN 2521 - 3512) 31, no. 1 (June 18, 2022): 202–19. http://dx.doi.org/10.31351/vol31iss1pp202-219.

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Co-crystals are new solid forms of drugs that could resolve more than one problem associated with drugs formulations like solubility, stability, bioavailability, mechanical and tableting properties. A preliminary theoretical study for estimating the possible bonding between the co-crystal components (paracetamol and naproxen) was performed using the ChemOffice program. The results revealed a high possibility for bonding between paracetamol and naproxen and indicated the ability of molecular mechanics study to predict the co-crystal design. In this work, four different methods were used for the preparation of three different ratios 1:1, 2:1, and 1:2 of paracetamol:naproxen co-crystals. The four methods are liquid-assisted grinding, solvent evaporation method, ultrasonic-assisted co-crystallization, and microwave-assisted co-crystallization. The characterization of the prepared co-crystal was performed by Fourier transform infrared spectroscopy, Thermogravimetric Analysis, Differential scanning calorimetry, Powder X-Ray diffraction, and Field emission scanning electron microscopy. The results showed that the most successful method for co-crystal production was solvent evaporation methods. The FTIR and DSC results indicated the formation of paracetamol-naproxen co-crystals when prepared by using the solvent evaporation method in the three ratios 1:1 (N1), 2:1 (N2), and 1:2 (N3). Moreover, the PXRD results confirm the previous conclusions. A solubility study was conducted to compare the water solubility of pure paracetamol and naproxen with co-crystals solubility. The naproxen solubility was improved by more than two times in (1:1) and (1:2) paracetamol/naproxen co-crystals. To conclude, this work succeeded in formation of new paracetamol/naproxen co-crystals, which can be considered as a new promising technique for formulation of these two drugs with an obvious enhancement in naproxen solubility and crystallinity. This could be exploited in preparation of tablets with possible enhancement in dissolution and bioavailability, however, further work is needed to prove this assumption.

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Mizutani, Ryuta, Yusuke Shimizu, Rino Saiga, Go Ueno, Yuki Nakamura, Akihisa Takeuchi, Kentaro Uesugi, and Yoshio Suzuki. "Visualizing soaking process of protein crystal." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1661. http://dx.doi.org/10.1107/s2053273314083387.

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Time-resolved visualization of the soaking process of tetragonal lysozyme crystal was performed by synchrotron radiation microtomography. Mother liquor containing hexachloroplatinate was introduced into a capillary bearing lysozyme crystals to visualize crystals undergoing soaking. The platinum distribution was first observed in the superficial layer of crystal and then gradually penetrated into the crystal core. The crystal structure of the platinum derivative in each soaking period was determined by time-resolved crystallography. A total of five platinum sites were identified in Bijvoet difference maps. These sites were classified into two groups on the basis of the time dependence of electron density development. A soaking process model consisting of binding-rate-driven and equilibrium-driven layers is proposed to describe the results. This study suggests that the structures of soaked crystals vary depending on the crystal position from which diffractions were taken.

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Sakamoto, Tatsuya, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, and Mineo Sato. "Development of Gas-Solid Phase Hybrid Synthesis Method of Single Crystal Ba₂SiO₄:Eu²⁺." Key Engineering Materials 485 (July 2011): 325–28. http://dx.doi.org/10.4028/www.scientific.net/kem.485.325.

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We succeeded in the single crystal growth of Ba2SiO4:Eu2+ by novel synthesis method which was gas (SiO) and solid (Ba - Sc - Al - Eu - O) phase hybridized. The Ba2SiO4:Eu2+ single crystal was synthesized by interfacial crystal growth after the reaction of the SiO gas with the surface of Ba - Sc - Al - Eu - O substrate in the reductive atmosphere. The single crystals were plate-like crystals with about 500 μm sizes and emitted green light around 500 nm under 300 - 450 nm excitation.

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Nugrahani, Ilma, and Rismaya Desti Parwati. "Challenges and Progress in Nonsteroidal Anti-Inflammatory Drugs Co-Crystal Development." Molecules 26, no. 14 (July 9, 2021): 4185. http://dx.doi.org/10.3390/molecules26144185.

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Co-crystal innovation is an opportunity in drug development for both scientists and industry. In line with the “green pharmacy” concept for obtaining safer methods and advanced pharmaceutical products, co-crystallization is one of the most promising approaches to find novel patent drugs, including non-steroidal anti-inflammatory drugs (NSAID). This kind of multi-component system improves previously poor physicochemical and mechanical properties through non-covalent interactions. Practically, there are many challenges to find commercially viable co-crystal drugs. The difficulty in selecting co-formers becomes the primary problem, followed by unexpected results, such as decreased solubility and dissolution, spring and parachute effect, microenvironment pH effects, changes in instability, and polymorphisms, which can occur during the co-crystal development. However, over time, NSAID co-crystals have been continuously updated regarding co-formers selection and methods development.

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Arnott, H. J., M. A. Webb, and L. E. Lopez. "An SEM study of raphide crystal initials in the leaves of vitis (grape)." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 984–85. http://dx.doi.org/10.1017/s0424820100141299.

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Many papers have been published on the structure of calcium oxalate crystals in plants, however, few deal with the early development of crystals. Large numbers of idioblastic calcium oxalate crystal cells are found in the leaves of Vitis mustangensis, V. labrusca and V. vulpina. A crystal idioblast, or raphide cell, will produce 150-300 needle-like calcium oxalate crystals within a central vacuole. Each raphide crystal is autonomous, having been produced in a separate membrane-defined crystal chamber; the idioblast''s crystal complement is collectively embedded in a water soluble glycoprotein matrix which fills the vacuole. The crystals are twins, each having a pointed and a bidentate end (Fig 1); when mature they are about 0.5-1.2 μn in diameter and 30-70 μm in length. Crystal bundles, i.e., crystals and their matrix, can be isolated from leaves using 100% ETOH. If the bundles are treated with H2O the matrix surrounding the crystals rapidly disperses.

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Yamagishi, H., M. Kuramoto, Y. Shiraishi, M. Machida, K. Takano, N. Takase, T. Iida, J. Matsubara, and Kazuya Takada. "CZ Crystal Growth Development in Super Silicon Crystal Project." Solid State Phenomena 57-58 (July 1997): 37–42. http://dx.doi.org/10.4028/www.scientific.net/ssp.57-58.37.

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Wittry, David B., and Nicholas C. Barbi. "X-ray Crystal Spectrometers and Monochromators in Microanalysis." Microscopy and Microanalysis 7, no. 2 (March 2001): 124–41. http://dx.doi.org/10.1007/s100050010080.

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Abstract Castaing’s successful implementation and application of the electron probe microanalyzer in 1950 stimulated a flurry of development activity around the world. The later versions of this instrument represented a truly international effort, with significant contributions by scientists from Europe, Asia, and North America. If the probe-forming system of the instrument was its heart, the X-ray wavelength spectrometer was its soul. This article reviews some of the history of spectrometer developments—lthrough the “golden years” of microprobe development, namely the dozen or so years following the publication of Castaing’s thesis, to the present. The basic physics of spectrometer and crystal design is reviewed. Early experimental devices, such as those developed by Castaing, Borovskii, Wittry, Duncumb, and Ogilvie are reported. Examples of commercial spectrometers such as those by ARL, MAC, Microspec, and Peak are described. Recent developments such as the combination of grazing-incidence optics with flat crystal spectrometers are noted, and the properties and uses of doubly curved crystals are discussed. Finally, the continued development of doubly curved crystal configurations, such as the “Wittry geometry” for scanning monochromators, and point-to-point focusing diffractors for producing small monochromatic X-ray probes to provide improved detection limits for microanalysis are considered.

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Kolb, Ute, Yaşar Krysiak, and Sergi Plana-Ruiz. "Automated electron diffraction tomography – development and applications." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 75, no. 4 (August 1, 2019): 463–74. http://dx.doi.org/10.1107/s2052520619006711.

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Electron diffraction tomography (EDT) has gained increasing interest, starting with the development of automated electron diffraction tomography (ADT) which enables the collection of three-dimensional electron diffraction data from nano-sized crystals suitable for ab initio structure analysis. A basic description of the ADT method, nowadays recognized as a reliable and established method, as well as its special features and general applicability to different transmission electron microscopes is provided. In addition, the usability of ADT for crystal structure analysis of single nano-sized crystals with and without special crystallographic features, such as twinning, modulations and disorder is demonstrated.

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Vaidya, Rajiv, Mehul Dave, and Kaushik R. Patel. "Electrical Properties of WSe2-X Single Crystals Grown By Direct Vapour Transport Technique." YMER Digital 21, no. 02 (February 17, 2022): 440–47. http://dx.doi.org/10.37896/ymer21.02/44.

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The single crystals of WSe2-x were grown by direct vapour transport technique. The grown crystals possess hexagonal crystal structure. The resistivities of the as grown crystals were measured using van der Pauw method. The Hall parameters of the grown crystals were determined at room temperature from Hall effect measurements. Electrical resistivity measurements were performed on this crystal in the temperature range 303–423 K. The crystals werefound to exhibit semiconducting nature in this range. The activation energy and anisotropy measurements were carried out for this crystal. The value of resistivity is increases with increasing selenium content. The results obtained are discussed in detail.

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Kiyonga, Emmanuel M., Linda N. Kekani, Tinotenda V. Chidziwa, Kudzai D. Kahwenga, Elmien Bronkhorst, Marnus Milne, Madan S. Poka, Shoeshoe Mokhele, Patrick H. Demana, and Bwalya A. Witika. "Nano- and Crystal Engineering Approaches in the Development of Therapeutic Agents for Neoplastic Diseases." Crystals 12, no. 7 (June 29, 2022): 926. http://dx.doi.org/10.3390/cryst12070926.

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Cancer is a leading cause of death worldwide. It is a global quandary that requires the administration of many different active pharmaceutical ingredients (APIs) with different characteristics. As is the case with many APIs, cancer treatments exhibit poor aqueous solubility which can lead to low drug absorption, increased doses, and subsequently poor bioavailability and the occurrence of more adverse events. Several strategies have been envisaged to overcome this drawback, specifically for the treatment of neoplastic diseases. These include crystal engineering, in which new crystal structures are formed to improve drug physicochemical properties, and/or nanoengineering in which the reduction in particle size of the pristine crystal results in much improved physicochemical properties. Co-crystals, which are supramolecular complexes that comprise of an API and a co-crystal former (CCF) held together by non-covalent interactions in crystal lattice, have been developed to improve the performance of some anti-cancer drugs. Similarly, nanosizing through the formation of nanocrystals and, in some cases, the use of both crystal and nanoengineering to obtain nano co-crystals (NCC) have been used to increase the solubility as well as overall performance of many anticancer drugs. The formulation process of both micron and sub-micron crystalline formulations for the treatment of cancers makes use of relatively simple techniques and minimal amounts of excipients aside from stabilizers and co-formers. The flexibility of these crystalline formulations with regards to routes of administration and ability to target neoplastic tissue makes them ideal strategies for effectiveness of cancer treatments. In this review, we describe the use of crystalline formulations for the treatment of various neoplastic diseases. In addition, this review attempts to highlight the gaps in the current translation of these potential treatments into authorized medicines for use in clinical practice.

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Okamoto, Takeshi, Takahiro Kanda, Yuichiro Tokuda, Nobuyuki Ohya, Kiyoshi Betsuyaku, Norihiro Hoshino, Isaho Kamata, and Hidekazu Tsuchida. "Development of 150-mm 4H-SiC Substrates Using a High-Temperature Chemical Vapor Deposition Method." Materials Science Forum 1004 (July 2020): 14–19. http://dx.doi.org/10.4028/www.scientific.net/msf.1004.14.

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To reduce the cost of silicon carbide (SiC) substrates, we have developed a high-temperature chemical vapor deposition (HTCVD) method for high-productivity crystal growth. We have conducted research using crystals of diameter 4 inches or less. In order to further reduce the cost, development of a 150-mm substrate has been demanded. With increasing crystal diameter, the occurrence of cracks should be suppressed efficiently. The internal structure of the furnace was designed to reduce the distribution of temperature in the radial direction of the crystal, ultimately reducing the stress responsible for the formation cracks. We demonstrated a 150-mm 4H-SiC substrate without cracks using by HTCVD method.

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Adams, Edward E., and Daniel A. Miller. "Ice crystals grown from vapor onto an orientated substrate: application to snow depth-hoar development and gas inclusions in lake ice." Journal of Glaciology 49, no. 164 (2003): 8–12. http://dx.doi.org/10.3189/172756503781830953.

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AbstractA laboratory experiment was conducted in which new ice crystals were nucleated from the vapor phase onto large existing ice crystals obtained from Antarctic lake ice. Flat, smooth ice-crystal surfaces were prepared, with c axes oriented either vertically or horizontally. When these were subjected to a supersaturated vapor environment, multiple individual crystals nucleated onto the substrates adopting the same crystallographic orientation as the parent. A dominant grain-growth scenario for kinetic-growth metamorphism in snow, which in some ways is analogous to the oriented morphologies in lake ice, is hypothesized. In the lake-ice-growth scenario, optimally oriented crystals will grow at the expense of those less preferentially positioned.The proposed dominant grain-growth theory for snow is in agreement with the observed decrease in the number of grains and the proximal similarity of crystal habit in kinetic-growth metamorphism in snow. Similarly, kinetic crystal growth on the interior of gas inclusions in Antarctic lake ice will also acquire the crystallographic orientation of the substrate ice. These small-faceted interior crystals significantly influence light scattering and penetration in the lake-ice cover.

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Lersten, Nels R., and Harry T. Horner. "Calcium oxalate crystals in tribe Galegeae (Leguminosae) including foliar crystal macropattern development in Caragana frutex." Canadian Journal of Botany 85, no. 4 (April 2007): 394–403. http://dx.doi.org/10.1139/b07-032.

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Galegeae was reported in 1987 to be unique among papilionoid tribes because calcium oxalate crystals were shown to be mostly lacking. We surveyed leaves of 45 species from 20 genera, mostly from herbarium specimens. A living species ( Caragana frutex (L.) K. Koch) with crystals was also studied developmentally, important because only three other species have been similarly studied. Herbarium specimens and various stages of C. frutex leaflets were bleached, dehydrated, cleared in alcohol–xylol, and made permanent. Freehand sections of C. frutex were mounted in glycerine. Crystals were detected microscopically and are generally lacking among Galegeae genera. This supports tentative contemporary opinion that the tribe is unnatural. Crystals provide new, potentially useful systematic data. Variously differing unicellular trichomes were also described in the survey. Caragana frutex leaflets have a previously undescribed macropattern development: crystals form only along veins, except for late-season prisms in scattered palisade parenchyma. Crystals form progressively base to apex, first following along successive major veins from midvein to margin and then in later-developing smaller veins, progressing acropetally. The midvein remains almost crystal-free until leaflets are at or near full size. Crystal macropattern development in C. frutex leaflets suggests that crystallization may be influenced by the whole organ, as well as by individual cells.

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Verkoelen, Carl F., Burt G. Van Der Boom, Adriaan B. Houtsmuller, Fritz H. Schröder, and Johannes C. Romijn. "Increased calcium oxalate monohydrate crystal binding to injured renal tubular epithelial cells in culture." American Journal of Physiology-Renal Physiology 274, no. 5 (May 1, 1998): F958—F965. http://dx.doi.org/10.1152/ajprenal.1998.274.5.f958.

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The retention of crystals in the kidney is considered to be a crucial step in the development of a renal stone. This study demonstrates the time-dependent alterations in the extent of calcium oxalate (CaOx) monohydrate (COM) crystal binding to Madin-Darby canine kidney (MDCK) cells during their growth to confluence and during the healing of wounds made in confluent monolayers. As determined by radiolabeled COM crystal binding studies and confirmed by confocal-scanning laser microscopy, relatively large amounts of crystals (10.4 ± 0.4 μg/cm2) bound to subconfluent cultures that still exhibited a low transepithelial electrical resistance (TER < 400 Ω ⋅ cm2). The development of junctional integrity, indicated by a high resistance (TER > 1,500 Ω ⋅ cm2), was followed by a decrease of the crystal binding capacity to almost undetectable low levels (0.13 ± 0.03 μg/cm2). Epithelial injury resulted in increased crystal adherence. The highest level of crystal binding was observed 2 days postinjury when the wounds were already morphologically closed but TER was still low. Confocal images showed that during the repair process, crystals selectively adhered to migrating cells at the wound border and to stacked cells at sites were the wounds were closed. After the barrier integrity was restored, crystal binding decreased again to the same low levels as in undamaged controls. These results indicate that, whereas functional MDCK monolayers are largely protected against COM crystal adherence, epithelial injury and the subsequent process of wound healing lead to increased crystal binding.

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Hayashi, Shotaro. "Elastic Organic Crystals of π-Conjugated Molecules: New Concept for Materials Chemistry." Symmetry 12, no. 12 (December 7, 2020): 2022. http://dx.doi.org/10.3390/sym12122022.

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It is generally believed that organic single crystals composed of a densely packed arrangement of anisotropic, organic small molecules are less useful as functional materials due to their mechanically inflexible and brittle nature, compared to polymers bearing flexible chains and thereby exhibiting viscoelasticity. Nevertheless, organic crystals have attracted much attention because of their tunable optoelectronic properties and a variety of elegant crystal habits and unique ordered or disordered molecular packings arising from the anisotropic molecular structures. However, the recent emergence of flexible organic crystal materials showing plasticity and elasticity has considerably changed the concept of organic single crystals. In this review, the author summarizes the state-of-the-art development of flexible organic crystal materials, especially functional elastic organic crystals which are expected to provide a foothold for the next generation of organic crystal materials.

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ANDRIANI, Debrina Puspita, and Masatoshi KURODA. "4C2 Preliminary Development of Crystal Orientation Map for EBSD by MATLAB Programming." Proceedings of Conference of Kyushu Branch 2013 (2013): 97–98. http://dx.doi.org/10.1299/jsmekyushu.2013.97.

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Muro, Takayuki, Yukako Kato, Tomohiro Matsushita, Toyohiko Kinoshita, Yoshio Watanabe, Hiroyuki Okazaki, Takayoshi Yokoya, Akira Sekiyama, and Shigemasa Suga. "Development of a soft X-ray angle-resolved photoemission system applicable to 100 µm crystals." Journal of Synchrotron Radiation 18, no. 6 (September 21, 2011): 879–84. http://dx.doi.org/10.1107/s0909049511034418.

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A system for angle-resolved photoemission spectroscopy (ARPES) of small single crystals with sizes down to 100 µm has been developed. Soft X-ray synchrotron radiation with a spot size of ∼40 µm × 65 µm at the sample position is used for the excitation. Using this system an ARPES measurement has been performed on a Si crystal of size 120 µm × 100 µm × 80 µm. The crystal was properly oriented on a sample stage by measuring the Laue spots. The crystal was cleavedin situwith a microcleaver at 100 K. The cleaved surface was adjusted to the beam spot using an optical microscope. Consequently, clear band dispersions along the Γ–Xdirection reflecting the bulk electronic states were observed with a photon energy of 879 eV.

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Baasandorj, Lkhagvasuren, and Zibin Chen. "Recent Developments on Relaxor-PbTiO3 Ferroelectric Crystals." Crystals 12, no. 1 (December 31, 2021): 56. http://dx.doi.org/10.3390/cryst12010056.

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Numerous investigations on the development of the relaxor-PbTiO3 ferroelectric crystals have been carried out since their extraordinary properties were revealed. Recent developments on these crystals have offered further advances in electromechanical applications. In this review, recent developments on relaxor-PbTiO3 crystals and their practical applications are reviewed. The single crystal growth methods are first discussed. Two different strategies, poling and doping, for piezoelectric improvement are surveyed in the following section. After this, the anisotropic features of the single crystals are discussed. Application perspectives arising from the property improvements for electromechanical devices are finally reviewed.

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Liang, Zhenye, Chen Tian, Xiaoxi Li, Liwei Cheng, Shanglei Feng, Lifeng Yang, Yingguo Yang, and Lina Li. "Organic–Inorganic Lead Halide Perovskite Single Crystal: From Synthesis to Applications." Nanomaterials 12, no. 23 (November 28, 2022): 4235. http://dx.doi.org/10.3390/nano12234235.

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Organic–inorganic lead halide perovskite is widely used in the photoelectric field due to its excellent photoelectric characteristics. Among them, perovskite single crystals have attracted much attention due to its lower trap density and better carrier transport capacity than their corresponding polycrystalline materials. Owing to these characteristics, perovskite single crystals have been widely used in solar cells, photodetectors, light-emitting diode (LED), and so on, which have greater potential than polycrystals in a series of optoelectronic applications. However, the fabrication of single-crystal devices is limited by size, thickness, and interface problems, which makes the development of single-crystal devices inferior to polycrystalline devices, which also limits their future development. Here, several representative optoelectronic applications of perovskite single crystals are introduced, and some existing problems and challenges are discussed. Finally, we outlook the growth mechanism of single crystals and further the prospects of perovskite single crystals in the further field of microelectronics.

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Ryu, Sun Young, In Hwan Oh, Sang Jin Cho, Shin Ae Kim, and Hyun Kyu Song. "Enhancing Protein Crystallization under a Magnetic Field." Crystals 10, no. 9 (September 16, 2020): 821. http://dx.doi.org/10.3390/cryst10090821.

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High-quality crystals are essential to ensure high-resolution structural information. Protein crystals are controlled by many factors, such as pH, temperature, and the ion concentration of crystalline solutions. We previously reported the development of a device dedicated to protein crystallization. In the current study, we have further modified and improved our device. Exposure to external magnetic field leads to alignment of the crystal toward a preferred direction depending on the magnetization energy. Each material has different magnetic susceptibilities depending on the individual direction of their unit crystal cells. One of the strategies to acquire a large crystal entails controlling the nucleation rate. Furthermore, exposure of a crystal to a magnetic field may lead to new morphologies by affecting the crystal volume, shape, and quality.

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Tsuyuguchi, Masato, Tetsuko Nakaniwa, and Takayoshi Kinoshita. "Crystal structures of human CK2α2 in new crystal forms arising from a subtle difference in salt concentration." Acta Crystallographica Section F Structural Biology Communications 74, no. 5 (April 16, 2018): 288–93. http://dx.doi.org/10.1107/s2053230x18005204.

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The catalytic subunits of protein kinase CK2 are classified into two subtypes: CK2α1 and CK2α2. CK2α1 is an attractive drug-discovery target for various diseases such as cancers and nephritis. CK2α2 is defined as an off-target of CK2α1 and is a potential target in the development of male contraceptive drugs. High-resolution crystal structures of both isozymes are likely to provide crucial clues for the design of selective inhibitors of CK2α1 and/or CK2α2. To date, several crystal structures of CK2α1 have been solved at high resolutions of beyond 1.5 Å. However, crystal structures of CK2α2 have barely achieved a low resolution of around 3 Å because of the formation of needle-shaped crystals. In this study, new crystal forms were exploited and one provided a crystal structure of CK2α2 at 1.89 Å resolution. This result, together with the structure of CK2α1, will assist in the development of highly selective inhibitors for both isozymes.

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Quattrosoldi, Silvia, René Androsch, Andreas Janke, Michelina Soccio, and Nadia Lotti. "Enthalpy Relaxation, Crystal Nucleation and Crystal Growth of Biobased Poly(butylene Isophthalate)." Polymers 12, no. 1 (January 18, 2020): 235. http://dx.doi.org/10.3390/polym12010235.

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The crystallization behavior of fully biobased poly(butylene isophthalate) (PBI) has been investigated using calorimetric and microscopic techniques. PBI is an extremely slow crystallizing polymer that leads, after melt-crystallization, to the formation of lamellar crystals and rather large spherulites, due to the low nuclei density. Based upon quantitative analysis of the crystal-nucleation behavior at low temperatures near the glass transition, using Tammann’s two-stage nuclei development method, a nucleation pathway for an acceleration of the crystallization process and for tailoring the semicrystalline morphology is provided. Low-temperature annealing close to the glass transition temperature (Tg) leads to the formation of crystal nuclei, which grow to crystals at higher temperatures, and yield a much finer spherulitic superstructure, as obtained after direct melt-crystallization. Similarly to other slowly crystallizing polymers like poly(ethylene terephthalate) or poly(l-lactic acid), low-temperature crystal-nuclei formation at a timescale of hours/days is still too slow to allow non-spherulitic crystallization. The interplay between glass relaxation and crystal nucleation at temperatures slightly below Tg is discussed.

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Migoń, Dorian, Tomasz Wasilewski, and Dariusz Suchy. "Application of QCM in Peptide and Protein-Based Drug Product Development." Molecules 25, no. 17 (August 29, 2020): 3950. http://dx.doi.org/10.3390/molecules25173950.

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AT-cut quartz crystals vibrating in the thickness-shear mode (TSM), especially quartz crystal resonators (QCRs), are well known as very efficient mass sensitive systems because of their sensitivity, accuracy, and biofunctionalization capacity. They are highly reliable in the measurement of the mass of deposited samples, in both gas and liquid matrices. Moreover, they offer real-time monitoring, as well as relatively low production and operation costs. These features make mass sensitive systems applicable in a wide range of different applications, including studies on protein and peptide primary packaging, formulation, and drug product manufacturing process development. This review summarizes the information on some particular implementations of quartz crystal microbalance (QCM) instruments in protein and peptide drug product development as well as their future prospects.

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Brinkman, W. F. "Electron Microscopy and the Electronics Industry: Partners in Development." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 12–13. http://dx.doi.org/10.1017/s0424820100178811.

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Since the invention of the transistor and the birth of the solid-state electronics industry, electron microscopy has been an integral part of the boom in the science and technology of semiconductors. The relationship has been symbiotic: the technique of microscopy has probably gained almost as much as the electronics industry from innovations. Historically, semiconductor research has always come down to a question of the growth of perfect materials with perfect interfaces, and microscopic analysis below the optical level has been essential to improvements. When applications for the semiconductors germanium and silicon were discovered in solid-state devices, its became necessary to grow high-quality single crystals free of defects. A lot of work at Bell Labs and other institutions was directed at understanding the behavior of dislocations in crystals. Bill Schockley, a co-inventor of the transistor, is well-known for his contributions to dislocation theory, particularly dislocation dissociation in semiconductors. Bob Heidenreich, from Bell Labs, contributed much to the early stages of microscopy of defects and dislocations. The need for dislocation-free material generated extensive efforts around the world which led to the growth of high-purity single-crystal silicon in the 1960’s. Silicon is now the highest quality and purest material available, and also the cheapest in single-crystal form.

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Lersten, Nels R., and Harry T. Horner. "Calcium oxalate crystal macropattern development during Prunus virginiana (Rosaceae) leaf growth." Canadian Journal of Botany 82, no. 12 (December 1, 2004): 1800–1808. http://dx.doi.org/10.1139/b04-145.

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In this first study of foliar crystal macropattern initiation and development, primordia to just-shed bud scales, stipules, and leaves were bleached, cleared, and viewed microscopically. Apical clusters of prismatics appear first in the 0.1-mm stipule; crystals proliferate basipetally as stipules elongate. Apical prismatics appear next in a 0.5-mm leaf; they remain isolated until tiny prismatics appear in scattered palisade cells throughout the lamina of a 1.0- to 1.5-cm leaf. Meanwhile, druses proliferate from stem through elongating petioles, reaching the base of 2- to 4-cm leaves. Lamina prismatics enlarge, and new ones appear. In the midvein, short files of tiny druses reach the apex of the 4- to 5-cm leaf, and files of druses extend into lower main lateral veins. In 9- to 11-cm (full-grown) mid-May leaves, lamina prismatics are numerous and conspicuous, but small druses have extended into smaller veins. Until leaf shedding, some lamina prismatics continue to enlarge, new ones form, and others become surrounded by tiny pris matics. Druses gradually occupy all vein orders, and many in the smallest veins become quite large with conspicuous cores. The mature crystal macropattern shows druses confined to stem, petiole, and leaf veins, whereas prismatics are localized in stipules, bud scales, and leaf lamina.Key words: calcium oxalate, crystal macropattern, druse, leaves, prismatics, Prunus, Rosaceae.

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Vitek, J. M., Stefano Beretta, S. A. David, and J. W. Park. "Microstructure Development in Single Crystal Welds." Materials Science Forum 426-432 (August 2003): 4123–28. http://dx.doi.org/10.4028/www.scientific.net/msf.426-432.4123.

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40

LU, YuDong, Jian'An HE, ZhiQiang ZHU, Bei'Er LV, HongWei MA, Mo HUANG, JiaJie FANG, and Long FU. "The development of quartz crystal microbalance." SCIENTIA SINICA Chimica 41, no. 11 (November 1, 2011): 1679–98. http://dx.doi.org/10.1360/032011-381.

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41

Lee, Alfred Y., Deniz Erdemir, and Allan S. Myerson. "Crystal Polymorphism in Chemical Process Development." Annual Review of Chemical and Biomolecular Engineering 2, no. 1 (July 15, 2011): 259–80. http://dx.doi.org/10.1146/annurev-chembioeng-061010-114224.

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42

Durif, André. "The development of cyclophosphate crystal chemistry." Solid State Sciences 7, no. 6 (June 2005): 760–66. http://dx.doi.org/10.1016/j.solidstatesciences.2004.11.022.

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43

Janbon, Sophie. "Effective crystal structures in pharmaceutical development." Acta Crystallographica Section A Foundations and Advances 74, a2 (August 22, 2018): e23-e23. http://dx.doi.org/10.1107/s205327331809486x.

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44

Vill, Volkmar. "The Development of Liquid Crystal Research." Advanced Materials 6, no. 7-8 (July 1994): 527–28. http://dx.doi.org/10.1002/adma.19940060702.

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45

Tang, Min, and Yi-Liang Li. "A Complex Assemblage of Crystal Habits of Pyrite in the Volcanic Hot Springs from Kamchatka, Russia: Implications for the Mineral Signature of Life on Mars." Crystals 10, no. 6 (June 23, 2020): 535. http://dx.doi.org/10.3390/cryst10060535.

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In this study, the crystal habits of pyrite in the volcanic hot springs from Kamchatka, Russia were surveyed using scanning electron microscopy. Pyrite crystals occur either as single euhedral crystals or aggregates with a wide range of crystal sizes and morphological features. Single euhedral crystals, with their sizes ranging from ~200 nm to ~40 µm, exhibit combinations of cubic {100}, octahedral {111}, and pyritohedral {210} and {310} forms. Heterogeneous geochemical microenvironments and the bacterial activities in the long-lived hot springs have mediated the development and good preservation of the complex pyrite crystal habits: irregular, spherulitic, cubic, or octahedral crystals congregating with clay minerals, and nanocrystals attaching to the surface of larger pyrite crystals and other minerals. Spherulitic pyrite crystals are commonly covered by organic matter-rich thin films. The coexistence of various sizes and morphological features of those pyrite crystals indicates the results of secular interactions between the continuous supply of energy and nutritional elements by the hot springs and the microbial communities. We suggest that, instead of a single mineral with unique crystal habits, the continuous deposition of the same mineral with a complex set of crystal habits results from the ever-changing physicochemical conditions with contributions from microbial mediation.

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Sztucki, Michael, Joachim Leonardon, Pierre Van Vaerenbergh, Jacques Gorini, Peter Boesecke, and Theyencheri Narayanan. "Development of a crystal collimation system for high-resolution ultra-small-angle X-ray scattering applications." Journal of Synchrotron Radiation 26, no. 2 (January 25, 2019): 439–44. http://dx.doi.org/10.1107/s1600577518016892.

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Crystal collimation offers a viable alternative to the commonly used pinhole collimation in small-angle X-ray scattering (SAXS) for specific applications requiring highest angular resolution. This scheme is not affected by the parasitic scattering and diffraction-limited beam broadening. The Darwin width of the rocking curve of the crystals mainly defines the ultimate beam divergence. For this purpose, a dispersive Si-111 crystal collimation set-up based on two well conditioned pseudo channel-cut crystals (pairs of well polished, independent parallel crystals) using a higher-order reflection (Si-333) has been developed. The gain in resolution is obtained at the expense of flux. The system has been installed at the TRUSAXS beamline ID02 (ESRF) for reducing the horizontal beam divergence in high-resolution mesurements. The precise mechanics of the system allows reproducible alignment of the Bragg condition. The high resolution achieved at a sample–detector distance of 31 m is demonstrated by ultra-small-angle X-ray scattering measurements on a model system consisting of micrometre-sized polystyrene latex particles with low polydispersity.

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Hartl, Walter P., Helmut Klapper, Bruno Barbier, Hans Jürgen Ensikat, Richard Dronskowski, Paul Müller, Gertrud Ostendorp, Alan Tye, Ralf Bauer, and Wilhelm Barthlott. "Diversity of calcium oxalate crystals in Cactaceae." Canadian Journal of Botany 85, no. 5 (May 2007): 501–17. http://dx.doi.org/10.1139/b07-046.

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The occurrence of various types of calcium oxalate crystals was studied in 251 species and subspecies of Cactaceae to determine whether they are useful characters for Cactaceae systematics. Crystal hydration states were identified by X-ray powder diffraction and polarizing microscopy as monoclinic calcium oxalate monohydrate (COM) and tetragonal calcium oxalate dihydrate (COD). Ninety-eight percent of taxa studied contained either COM or COD crystals, or both. Different morphologies of crystals were further defined by light microscopy and scanning electron microscopy as druses, raphides, styloids (prisms), and crystal sand. In particular, the preponderance of one of the hydration states (COM or COD) was characteristic for certain Cactus subfamilies. Data showed that in Pereskioideae, Maihuenioideae, and Opuntioideae COM is predominant, while in Cactoideae COD prevails. In the remainder of Cactoideae, the crystals were quite variable. In tribe Hylocereeae, many species form both COM and COD as well. In the genera Hylocereus , Epiphyllum , Selenicereus , and Weberocereus , COM forms were almost exclusively represented by raphides together with different crystal forms in their epidermal cells. In the remainder of the Cactoideae, crystals did not follow any observable patterns. Development of crystallographic standards for identifying crystal forms microscopically is proposed for future crystal studies.

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Lagoeiro, Leonardo, Paola Ferreira, and Cristiane Castro. "Crystallographic Control on the Development of Texture in Precipitated Quartz Grains." Materials Science Forum 495-497 (September 2005): 57–62. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.57.

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In this study we analysed microstructures and determined [c]-axis textures of quartz crystals in veins formed parallel to composition banding in naturally deformed iron oxide-quartz rocks. Only veins of few millimeters thick were sampled. These veins were formed in a regime of non-coaxial deformation under temperature of ~300°C. We made thin sections from rock slabs cut perpendicular to shear plane and parallel to shear direction. In thin sections veins are composed of large single quartz crystals of lens or rhomb-shaped blocks similar to s-porphyroclast systems. Lattice distortion (i.e. undulose extinction, gradual lattice banding and subgrain boundaries) occurs in single crystals as revealed by optical microscopy. Distortion was caused by slip of dislocations preferentially on basal planes. These are also planes along which microcracks developed. Distinct types of microcracks are individualized based on size, orientation and distribution of voids. Microcracrack voids are filled by polycrystalline quartz aggregates. In contrast to single crystals, these aggregates do not have any optical microstructure that might be related to crystal plastic process. Moreover grain size distribution are quite different from those related to dynamic recrystallized aggregates. Despite of that, polycrystalline quartz aggregates have strong [c]-axis preferred orientations. These orientations are similar to those of single crystals close to the microfracture walls. In large spaced voids c-axes orientation of quartz in polycrystalline aggregate have significant misorientation angles with respect to the single crystal [c]-axis orientation, reaching values up to 45° to the foliation plane (XY section of the finite strain). Based on microstructural and textural data we propose a mode for quartz [c]-axis texture development in both single crystals and polycrystalline aggregates that fill microcrack voids.

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Kumar, Saroj, Om Prakash, Amresh Gupta, and Satyawan Singh. "Solvent-free Methods for Co-crystal Synthesis: A Review." Current Organic Synthesis 16, no. 3 (June 17, 2019): 385–97. http://dx.doi.org/10.2174/1570179416666190329194926.

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Background: Pharmaceutical co-crystals are the homogeneous crystalline substances composed of two or more substances bound together in the same crystal lattice via noncovalent interactions like hydrogenbonding, electrostatic interaction and Vander Waals interactions. Currently, co-crystals provide excellent opportunities to the formulation scientists in developing new pharmaceutical products by improving the pharmaceutically significant properties like solubility, dissolution rate, bioavailability, stability, and some other derived properties. Due to their ability to improve pharmacokinetic performance and their important intellectual property status, co-crystals are likely to have a very significant role in future drug development. Thus, formulation scientists have their focus on the development aspects of a co-crystallization process that include a rational selection of co-former, the discovery of novel synthetic procedures and new characterization techniques, and large scale production of these novel materials. Objective: The objective of this article is to present an extensive review of solvent-free methods for co-crystal synthesis, mainly focusing on the principle mechanisms, advantages, and drawbacks of each method. Conclusion: From the review of the topic, it is clear that the solvent-free methods can offer numerous advantages over solvent-based methods in the design and the production of co-crystals of pharmaceutical use and these methodologies can also pave the path to advancing the field of co-crystal synthesis. Some of the advantages accompanied with solvent-free methods are the use of no or very less amount of solvent(s), exceptional purity and quality of produced co-crystal, large scale production and the short reaction times in few cases.

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Jakubowska, D., J. Zdunek, M. Kulczyk, J. Mizera, and K. J. Kurzydłowski. "Microstructure Evolution and Texture Development in a Cu-8.5%AT. AL Material Subjected to Hydrostatic Extrusion." Archives of Metallurgy and Materials 61, no. 2 (June 1, 2016): 933–36. http://dx.doi.org/10.1515/amm-2016-0158.

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AbstractThe aim of the present paper was to investigate microstructure and texture evolution of two single crystals and polycrystal of Cu-8.5%at.Al material. All of mentioned samples were deformed by HE to achieve true strain ε = 1.17. For microstructure analyzes observations by transmission electron microscope (STEM) were done. Crystalline size for samples after SPD were determine using XRD method. The global texture measurements were done using Bruker D8 Discover diffractometer equipped in Cr radiation. Microstructure investigations revealed nanocrystalline structure in single crystals with initial orientations <110> and <100> and polycrystalline Cu-8.5%at.Al material after SPD. The global texture measurements have shown the stability of initial orientation of <100> Cu-8.5%at.Al single crystal after HE, whereas the same SPD process strongly brakes up the orientation <110> Cu-8.5%at. Al single crystal.

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Journal articles on the topic 'Crystal development'

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